 Hello everyone and again welcome to the fruit school, especially the blueberry production series of it. We're going to have six different sections and 12 different speakers. For today, I'm planning to present some information on blueberry cultivar selection, since this is the first think a grower or a future grower needs to consider when deciding to plant some blueberries. So let me just share some general information about blueberry cultivation in Alabama. We all know that blueberries are a high value fruit crop that is becoming very popular not only in our nation but worldwide. And with that, according to the 2017 census data, Alabama's blueberry farm gate value has increased recently and right now or right in 2017 we had 536 blueberry farms and 834 acres planted with blueberries in Alabama. But you're probably aware that there are different types of blueberries and the one that is widely popular and widely grown in Alabama is called rabbit-eyed blueberry or thexinia mashae. And there are different good reasons for that. The first one, this plant is native to the southeastern United States. The blueberries are very vigorous and productive. They are long-lived and very easy to care. They're also drought tolerant, which is not the case with, let's say, some southern hibiscus. So they can grow successfully in lower organic matter soils and that is the prevalent type of soils that we have in the state of Alabama. Usually the organic, good organic matter would be around 2%, but especially in the eastern part, the southeast part of the state, many farms are showing about only half percent of organic matter in their soils. So to amend the soil for production of southern hibiscus, it will require a lot of amendments and big investment, but rabbit eyes can go by if the organic matter in the soil is around 2%. They are also possessing high nutraceutical value and a lot of health benefits are related to blueberry consumption and that is because the antioxidants can fight the free radicals. So there are benefits for controlling some cardiovascular diseases and some cancers and a lot of other benefits to your health. Also, rabbit eyes are very versatile. They can be consumed fresh. They could be frozen for later use and they could be processed in different juices and jellies and gems and just a nice crop. With that, what we need to consider when we start our cultivar selection. Again, the most important thing when a grower decides to plant some blueberries. First of all, we need to consider our location in the state and what is our climate and especially what is the USDA zone, climatic zone, hardiness zone in Alabama where we live and going to plant those blueberries. So, being aware of our climate because we will need to match our climate with the biology of the cultivars that we're going to grow. The second important thing would include the soil conditions and of course this relates to the soil pH which blueberries usually require a pH that is more on the acidic side somewhere between 4.5 to 5.2 pH. And also, as I mentioned, the organic matter in the soil also is important but rabbit eyes will go by when the organic matter is about 2%. Also, it's important to have your marketing strategy before you plant your blueberry bushes and considering if you're going to have pick your own operation or a big commercial operation and how you're going to harvest your crop every year. All those are important factors that need to be matched to the plant biology and recently the chilling power requirements that each cultivar is needing for proper development in the spring and proper crop production are becoming more and more important, especially with the warming trends in the climate that we're seeing in some of the last winter seasons. So, we need to be aware of when our plants are going to bloom. If the bloom happens very early in the season, the risk of freeze and frost damage is usually increased and then for marketing purposes, when our crop is going to ripe, we need to be aware of that. What is the yield potential of each cultivar that we're selecting to plant and how consistently the cultivar is cropping is also very important. And then we need to be aware of the fruit quality of the particular cultivar. And you probably have harvested some blueberries already and you know that at harvest, some of the stems when we pick the blueberries, they're causing some cracks and this opening of the skin is kind of inviting some diseases to occur, secondary infections can happen and the storage life of those blueberries is being much reduced. Shipping qualities are also being reduced. And there are other qualities like the size and the number of the seeds. Also, consumers are looking at the darkness of the skin. So, a lot to consider. And again, the harvesting method if you're going to have pick your own operation, or if you consider some machine harvesting, then you need to look at some cultivars that are probably going to have more concentrated ripening. Less harvest during the season. Okay. As I have mentioned different requirements. It is good to know that we have a couple of breeding programs in the region in the southeast and right now. For the last year, Auburn University, we're very happy to welcome Dr. Su Shanru, who is our blueberry, new blueberry breeder, and we also have another colleague Dr. Melba Salazar, who is our blueberry one physiologist. So, with their help, we hope that very soon we're going to have some new selections with highly desirable traits for advanced testing in different locations in Alabama. But for now, we needed to test some of the UGA developed and released cultivars that we did not have information about their performance in our climate before. And some of them include the cultivar O'Clockney that was released in 2002, Vernon was released in 2004. And recently, the breeding program from the University of Georgia released two large-rooted rabbit eye cultivars, and those are Titan and Cure. So we didn't have information on their performance in our states. And my talk today is going to present some of the research done so far. So we're looking at an interesting USDA released that is called Pink Lemonade, and it is recommended for homeowners mainly, not for commercial production. But because of the wonderful qualities, we wanted to look at the performance of this cultivar in Alabama as well. So today I'm going to present the results and trying to summarize the information from two studies conducted in two different locations in Alabama. The first of the studies was initiated in 2011, and it was conducted in North Alabama, or North Alabama Horticulture Research Center in Kalman. We had rooted plants from the Breeder at University of Georgia. He gave us for testing five of the recently released cultivars and five of his plants selections. They were potted and grown until they became three years old, and then we are assessing the cultivar response to the growing conditions in North Alabama. So first of the cultivar cultivars that we received from Georgia, and first of them, it was still unnamed selection T9-59, and now it's the released cultivar Titan. Then we had Vernon, Glockney, Alapaha, Brightwell, and five more selections that were not considered for release by the Breeder. And here you can, in the picture, you can see the crew at the station helping to plant those bushes. So we were evaluating everything in terms of biological, in order to kind of determine the biological requirements for those cultivars. And of course, we started with flowering progression, and we were pleased to see that this new cultivar Alapaha, which has relatively early ripening, is actually having very late blooming. What does this mean, like in years like this last season, when there is a big risk of frost and freeze damage, this cultivar can escape some, to some extent at least, the damage to the flowers and can produce some decent growth. Also, as I mentioned, it's important to determine what is the season of ripening for all those cultivars. And we can see from this chart that our Alapaha, Titan, and Vernon cultivars, they all started to ripen in mid-June in our North Alabama location. And before then, we had three of the selections with very early ripening, but again, none of them got released by the Breeder. And we were interested if the season could be a little bit extended, season of ripening. So we had Briteville and Cloakney that really started to ripen very late. The most important quality of any cultivar is the cropping potential or the yield that the cultivar would produce. And not surprisingly, here for those three years, the yield per plant is being presented on this chart and we can see that Titan was the cultivar that is producing the highest yield. And it was followed by Vernon and Alapaha and also Briteville. So all those cultivars produced very good to excellent yield throughout the years. Cloakney here was an exception and this was a surprise to us as the Breeder describes this cultivar with being highly productive. But one of the reasons for this to happen may have been the proximity to our pollinizer. Usually a Cloakney needs a good pollinizer and powder blue is being recommended as the companion cultivar for a Cloakney. And since we had this in another study that was nearby and we wanted to save on some space to plant more of the newer selections and test them. We relied on this pollinizer but probably part of the problem was the lack of good pollination for Cloakney. This chart represents the yield data for the years starting in 2013 to 2017 when actually the station in Kalman got closed and we couldn't collect any more data on the performance of those plants. But you can see that in general the same tendency of cropping was confirmed for the five years period like Alapaha was number one producer with 46 pounds per plant cumulative yield for those five years. And it was followed by Titan and Brightwell with virtually the same type of total yield produced. Vernon was also a good producer, again a Cloakney was provided the lowest crop. I mentioned that especially Titan here was introduced and tested because of the size of the fruit that was reported by the breeder to reach about three and a half, four grams on average. While a typical blueberry would produce an average fruit size of about two grams only. So we can see from this chart that Titan really had the largest fruit throughout the study and it reached about three and a half grams on average. And it was followed by the fruit size of Vernon, which also produced average fruit size of about two and a half grams. Alapaha was producing the smallest berries but of course being an early season cultivar. This is pretty typical for the early season cultivars. So to summarize some of our impressions from the study in North Alabama, we saw that Alapaha really had late blooming, even though it happened early with with climax. And Alapaha has about 450 to 550 chilling power requirements. This is a very good cultivar because it can help to avoid or to reduce the risk of freeze of spring freeze and frost damage. And we might be able to see this this year, very clearly in another study. So Alapaha has this early ripening, which means you can get a higher premium price for the fruit. Also, the fruit is small to medium size, but otherwise delicious. Alapaha is the highly productive cultivar, as obvious from this study. The cultivar we were interested was Titan. Titan has between 500 to 550 chilling power requirements. It is also an early season ripening variety with very large berry size, the largest from this test in comparison to the other 10 cultivars. Titan fruit has excellent firmness, but the fruit has a tendency to crack when the conditions are kind of wet. So if the season is rainy, you can expect those cracks, unless it is grown in some type of protected environment, probably a lot of the fruit will crack. Titan has this type of vigorous and healthy plant and is highly productive in North Alabama. So what we saw for Vernon that is having like between 500 and 550 chilling hours. It has also vigorous plant with moderately spreading habit, growing habit. It has early season ripening with relatively large size berries, of course smaller than Titan, but still pretty good size. The flavor is excellent, nice color and nice firmness for Vernon. O'Clockney is the cultivar among this group that requires the highest number of chilling towers to develop and produce good crop. It is a late season ripening rabbit eye cultivar with vigorous and upright plants, but in this experiment in North Alabama, the productivity was relatively low. And it was the lowest among all cultivars that we tested there. Of course, one of the reasons that we think of this providing this low productivity was the proximity of the powder blue is a companion cultivar. It wasn't planted directly in the adjacent rows, it was planted in an adjacent planting. So to summarize our impressions from this trial, we saw that during the initial years of establishment cultivars a lot of Titan and Vernon produced high yields. Titan had the largest berries, about three and a half grams on average. Vernon also produced large berries of over two and a half grams. A laparca matured very early, even though it flowered late. So with that, I'm going to transition to newer experiment that we're recently conducting in Central Alabama. It is again based on three year old potted plants that were planted at the Children Research and Extension Center in 2018. And this experiment is grown under conventional production system. The cultivars that we're testing here include a laparca, climax, premiere, cruel, Titan, Vernon, teeth blue, outer blue, o'clockney, and this pink lemonade that you can see on the picture. So in 2020, we let the plants grow and establish their root system. We allowed just a few berries on the plants. We kind of tinned out almost all of the fruit, kind of focusing on the development of a good root system during this period of time. So we did not collect data on yield in 2020, but we started monitoring for the season to determine the season of ripening and some fruit quality data. So in 2021, we collected the full set of data for all those cultivars. What we noticed a laparca, Vernon, cruel, and premiere started to ripen about 10 to 15 days earlier here in Central Alabama in comparison to our North Alabama location. And then climax, Titan, and pink lemonade, they started ripening about five days later after the first group of cultivars. And finally, we had a group of late season cultivars that included powder blue, teeth blue, and o'clockney. And they started ripening about two weeks after the initial ripening was recorded for the first set of cultivars. Here is our data for the total yield per plant in 2021, or the last season. As you can see, just in controversy to what we saw in North Alabama, our o'clockney plants here were the highest, provided the highest yield of 8.6 pounds per plant on average. And then we had teeth blue and powder blue producing 7.3 kilograms per plant on average. And a cruel and a laparca had between five and a half to six kilograms per plant. What was our surprise here was to see that Titan produced really very low yield. Part of it might have been that we got a lot of rain during this ripening season, and a lot of Titans berries have cracked so they considered them unmarketable, we didn't harvest them, we did not report on the yield for them. So this was the marketable yield that we were getting from Titan in this last season in central Alabama. And not surprisingly, pink lemonade had also very low crop. So here is our data for the mean berry size for the last two seasons. And you can see that cruel and Titan were producing the largest fruit in both seasons. And our a laparca and pink lemonade kind of consistently had those smaller fruit size. And it is also important to look at the sweetness of the fruit and in both seasons, teeth blue provided the sweetest fruit in our central Alabama location. And it is also worth to notice that the 2021 we had this rainy, rainy season, rainy summer, and probably this contributed to the lower sugars that we saw in the berries in general in 2021. So some of the conclusions of course this study just almost just started and we need to evaluate the fruit and quality in multiple seasons, but our initial impressions from a laparca are kind of confirming our conclusions from the study in central Alabama, since this plant had very similar performance, very, very good cultivar, great producer. Titan, we noticed the last season at least in central Alabama was not as productive as those plants performed in North Alabama. Produced better crop than Titan in the central Obama location. And a clopney surprisingly for us had the highest yield in central Obama in comparison to our cultivars that we were evaluating there. So cruel is one of the newest probably the newest rapid I release from University of Georgia. It has relatively low chilling power requirements between 350 and 400 chili hours are required. The ripening is early season for cruel. Very size is really very large. Very similar to Titan. Better fruit form is then probably then Titan, and the plants are vigorous and highly productive. The seeds inside though are a little larger. And the next cultivar I wanted to highlight this is the pink lemonade, which is very attractive, very unique pink color. But again, this cultivar has relatively low chilling requirements between two and 300 only the size of the fruit is relatively small. In central Obama, this cultivar ripened in the middle of the season, even though the literature suggests it is it has late ripening, but it's in some other environments. So the yield for us was very low. This is the major reason why it's not recommended for commercial production maybe, but the taste is very distinct and you can see the appearance is very attractive. Those berries, once they start ripening, they can soften really really very fast. So what you can do you can harvest them with some fruit that is not completely ripe, and the taste is your amount of the feeling is real real good. So talking about the biology of the plants and our environment and why we need to match the plant biology with our location and the conditions in our location. Probably those pictures that I'm going to show you and the story I'm going to tell you from this last season is going to explain why it is so important. Now what you're looking at on the screen, we're having some cruel plants. I mentioned that cruel requires between 350 and 400 chili hours for a successful development and crop production. And you can see on the first picture on January 11 of this year. So early in the season, those flowers were open and we had about 30 to 40% on different plants of the flowers already open in the beginning of January. So it is unusually warm December, warm for for a winter month, but still had those temperatures that help to accumulate and satisfy the chilling requirements for this cultivar. So when January came, the cultivar was ready to open its flowers. And a month later, you can see how those plants were looking we had close to 80% of the flowers open, but we are well aware that the risk of frost and freeze events in Alabama is going to expire in mid-April. So we were really worrying what is going to happen to our plants, especially with cultivars like Crure that kind of bloomed that early. And by the way, flowering for blueberry plants was earlier than usual for the entire Southeast region this year. But just to compare with some other cultivars, you can see on this picture that climax bugs were either completely closed or just starting to swell. So we're aware that this plant phenology is closely related to the environmental factors, and we're pretty aware that if the bud is still dormant like this one, any freeze wouldn't have any effect on the buds. At this stage probably if 21 degrees Fahrenheit temperature can happen, can occur, there will be some damage to the buds. But it was early January and those plants were developing relatively fast, even though the climate was behind Crure. So in January and February, we're experiencing some freezing temperatures. So we decided to cover our plants. We have four rows of blueberries at this location and those are our raw covers. We used to protect the plants. By the way, the literature says that if you use a single layer of raw covers, it can increase the temperature beneath by about two degrees. If you use like double layer of raw covers, the temperature inside could be increased by eight to 10 degrees. And when we measure the temperature outside and inside we saw like eight degrees difference for the plants that were covered with those raw covers. Also, we tried to keep the soil moist, as moist as possible to try to protect our plants. But we're aware that individual flowers, when the individual flowers are distinguishable, they could be killed at temperature of 25 degrees Fahrenheit. And when the flowers are separated with their corollas closed, they could be killed at 28 degrees Fahrenheit. Fully open flowers like you saw for February development of Crure, they could be damaged at 29 degrees Fahrenheit. And if you'd like more information about the plant phenology and risk temperatures, you can look at this publication that is from the Alabama Covertive Extension System. So what happened on March 11 and 12 of this year, the temperatures in this central Obama location, they went to 24 degrees Fahrenheit. So, as you can imagine, those blueberry plants that were very advanced in their development and had fully open flowers, they were, they were severely severely damaged. Unfortunately, those plants were covered before the event, of course, but two of the rows, they were blown by, the covers were blown by the wind. So as a consequence, we saw difference in the responses of Crure and other cultivars after the freeze event on March 15. And here, those pictures would demonstrate to you how the uncovered two rows of plants were looking in comparison with the plants that were protected. During this time that still have some surviving crop and they might produce some crop this year. So this is a very good example of the use of some protective environment for the production, especially for those cultivars that have low chilling requirements. And here, I'm representing the data for cold damage based on the two rows that were covered, and those bars that are in green, they represent the cover cultivars that have some more higher percent survivability of their flower buds and their fruit, and the purple bars here, they represent the averages for the plants that were not covered where the cover was actually blown by the wind. And you can see from this picture that our O'Clockney and chief blue cultivars had the highest percent survivability, but we also had Crure and Climax and Alapaha that that might have like 30 to 40% of their flowers and fruit surviving these conditions. While for Climax and Alapaha and powder blue that were without the cover actually, the percentage of damage is 100% loss of crop. So this is kind of underlying the significance of knowing the plant biology and the conditions in your area. To summarize this information, probably we would not recommend planting of Crure plants in central Obama unless they're under some type of protective environment like greenhouse or some other protection because of their early satisfaction of chilling requirements early bloom and the damage caused by the freeze events. Trials will continue to determine the best performing clavidae blueberry cultivars for sustainable production in various environmental conditions in the state. And with that I wanted to acknowledge the assistance from Maggie Price who is in the team at the research station and children, and also Arnold Koehler who is now retired, but the entire team at the station in Coleman, who helped to collect data and conduct our studies and is conducted with the support of Specialty Crop Law Grants of the Alabama Department of Agriculture and Industry.